Evolution: artificial selection and domestication

In the 18th and 19th century evolutionary biologists, including Darwin, emphasised the...

In the 18th and 19th century evolutionary biologists, including Darwin, emphasised the similarities between natural evolution and artificial ‘ improvement’ of livestock under domestication. They believed that studying domesticated animals and plants could illuminate the mechanisms of natural evolution.

When you have completed this unit you should be able to:

define the terms ‘artificial selection’ and ‘domestication’ and explain the relationship between artificial and natural selection;

describe some forms of dwarfism in modern breeds of dogs and explain their relationship to dwarfism in humans and in modern and extinct wild mammals;

describe some features of the skin, fur, feathers and the shape of the head frequently observed in domesticated livestock;

outline some major conclusions emerging from the sequencing of the dog genome and outline some current theories about when and where dogs were domesticated;

explain the functional basis of some of the anatomical changes induced by selective breeding of some modern dog breeds;

describe experimental domestication in foxes and explain its relevance to the origin of anatomical and behavioural characteristics in modern breeds of dogs and other livestock;

measure some anatomical changes induced by selective breeding of bulldogs during the last hundred years and use the data to assess functionality and rates of evolutionary change.

Evolution: artificial selection and domestication

Introduction

Most contemporary evolutionary biologists study evolution experimentally using laboratory organisms such as Drosophila or natural systems in the wild. However, 18th and 19th century evolutionary biologists, including Darwin, emphasised the similarities between natural evolution and artificial ‘ improvement’ of livestock under domestication. They believed that studying domesticated animals and plants could illuminate the mechanisms of natural evolution. Indeed, Chapter 1 of On the Origin of Species… is entitled ‘Variation under domestication’. Recent discoveries reveal the relationship between natural evolutionary mechanisms and the practical technologies used to breed plants, animals, yeasts and, these days, microbes, to produce food, clothing, transport, companionship, decoration, entertainment and most recently medicines. This unit is mostly about mammals, particularly dogs and other domesticated livestock, but the basic principles are probably universal. Dogs and other livestock are so familiar that we hope that you will take the opportunity to observe the characters, habits and processes described in this unit in animals that you see around you.

This unit is an adapted extract from the course Evolution (S366) [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] .

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